FEM: inout tetgen converter, guard Gui commands to be able to load the module in CMD mode without problems

src/Mod/Fem/feminout/convert2TetGen.py

@@ -26,11 +26,12 @@
 
 # Make mesh of pn junction in TetGen format
 import FreeCAD
-import FreeCADGui
+App = FreeCAD  # shortcut
+if FreeCAD.GuiUp:
+    import FreeCADGui
+    Gui = FreeCADGui  # shortcut
 # import Part
 import Mesh
-App = FreeCAD  # shortcut
-Gui = FreeCADGui  # shortcut
 
 ## \addtogroup FEM
 #  @{
@@ -277,22 +278,26 @@ def createMesh():
     nmesh.removeDuplicatedFacets()
     pnMesh.Mesh = nmesh
 
-    # Hide all boxes
-    for box in BoxList:
-        Gui.hideObject(box)
-    # # Remove all boxes
+    if FreeCAD.GuiUp:
+        # Hide all boxes
+        for box in BoxList:
+            Gui.hideObject(box)
+ 
+    # Remove all boxes
     # for box in BoxList:
     #     App.ActiveDocument.removeObject(box.Name)
 
     # Update document
     AppPyDoc.recompute()
 
-    ## export to TenGen *.poly (use File|Export instead)
+    # export to TenGen *.poly (use File|Export instead) *****
     # filePath = "/home/tig/tmp/tetgen/pnJunction.poly"
     # exportMeshToTetGenPoly(pnMesh.Mesh,filePath,beVerbose)
 
-    Gui.activeDocument().activeView().viewAxometric()
-    Gui.SendMsgToActiveView("ViewFit")
+    if FreeCAD.GuiUp:
+        Gui.activeDocument().activeView().viewAxometric()
+        Gui.SendMsgToActiveView("ViewFit")
+
     if beVerbose == 1:
         FreeCAD.Console.PrintMessage("\nScript finished without errors.")